[Qemu-devel] [PATCH] pci: fix requester id to be the one on root bus

[Peter Xu <peterx@redhat.com>]

When there are devices under PCI bridge (or bridges), PCI requester ID
should be the one that hooked on the root PCI bus, not the PCI device
itself.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/pci/msi.c         | 2 +-
 hw/pci/pci.c         | 9 +++++++++
 include/hw/pci/pci.h | 2 ++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/hw/pci/msi.c b/hw/pci/msi.c
index e0e64c2..1719716 100644
--- a/hw/pci/msi.c
+++ b/hw/pci/msi.c
@@ -315,7 +315,7 @@ void msi_send_message(PCIDevice *dev, MSIMessage msg)
 {
     MemTxAttrs attrs = {};
 
-    attrs.requester_id = pci_requester_id(dev);
+    attrs.requester_id = pci_requester_id_recursive(dev);
     address_space_stl_le(&dev->bus_master_as, msg.address, msg.data,
                          attrs, NULL);
 }
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bb605ef..c14299b 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2498,6 +2498,15 @@ PCIDevice *pci_get_function_0(PCIDevice *pci_dev)
     }
 }
 
+uint16_t pci_requester_id_recursive(PCIDevice *dev)
+{
+    while (pci_bus_num(dev->bus)) {
+        /* This is not on root PCI bus, we find its parent */
+        dev = dev->bus->parent_dev;
+    }
+    return pci_requester_id(dev);
+}
+
 static const TypeInfo pci_device_type_info = {
     .name = TYPE_PCI_DEVICE,
     .parent = TYPE_DEVICE,
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index ef6ba51..4cb5b50 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -776,4 +776,6 @@ extern const VMStateDescription vmstate_pci_device;
     .offset     = vmstate_offset_pointer(_state, _field, PCIDevice), \
 }
 
+uint16_t pci_requester_id_recursive(PCIDevice *dev);
+
 #endif
-- 
2.4.11